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J. G. HARRIS. METHOD OP GRAINING PLATES POR SURFACE PRINTING.

Patented NOV. 6, 1888..

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raras JABEZ G. HARRIS, OF PROVIDENCE, RHODE ISLAND, ASSIGN OR TO HARRIS 85 .I ONES, OF SAME PLACE.

METHOD OF GRAINING PLATES FOR SURFACEUPRlNTl-NG.

SPECIFICATION forming part of Letters Patent No. 392,556, dated November 6, 1888.

Application filed October 14, 1887. Serial No. 252,393. (No model.)

To all whom it may concern:

Beit known that I, JABEZ G. HARRIs, a citizen ofthe United States, residingat Providence, in the State of Rhode Island, have invented a new and useful Improved Method of Graining Plates for Surface-Printing, of which the following is a specification.

My invention relates to an improvement in the art of graining the surface of plates for lithographie or zincographic printing; and it consists in the improved method of producing the required grain by covering the surface of vthe stone or zinc plate with sand and rolling the said sanded surface with spherical balls, Which,having a limited point of contact,serve to press the sand against the plate without tendency to produce scratches or to Wear the plate unevenly.

Figure l is a view showing a vertical section of the shaking bed employed to carry out my invention. Fig. 2 is a plan view of the same. Fig. 3 is au enlarged detail section showing the plate, the spherical balls, and the layer of sand.

In the accom panying drawings, A represents the bed, upon which the zinc plate Bis secured by means of tacks c at its edges or otherwise. The bed A is provided with the raised sides O O, and is provided with the supporting-wheels D D,which run upon the tracks E E. The shaftE is held in the stands G G and is provided with the slotted crank-disk H, from which connection is made to the bed A by means of the pitman I. Upon the plate B is placed a quantity of sand, c, and also a number of spherical balls, b, which are preferably made of glass. The rotary movement of the shaft F will cause a reciprocating movement of the bed A and the attached plate, which at the proper rate of speed and throw will impart a rolling movement to the spherical balls, thus serving to press the grains of san'd against the plate, and thus producing the finely-grained surface required for the purpose of surfaceprinting; and in order to secure the best result I also add a supply of water to the sand and spherical balls,which are preferably about the size of large marbles. In this case the desired effect upon the plate will be produced with great rapidity and of fine quality.

Instead of the zinc plate B,which is attached to the bed A, a lithographie stone plate may be grained by the same process, the stone being let into a recess in the bed or otherwise arranged so that the sand and balls can have asurroundinglevel surface over which to move, in order to be able to grain the surface of the stone to its extreme edges.

I claim as my invention- Themethod of graining the surface of metallic or stone plates for surfaceprinting, which consists in reciprocating the said plate under a quantity of sand or sand and water in contact with the surface of the plate with a number of balls which roll upon the sanded plate and operate to press the sand against the said plate,

lsubstantially as described.

JABEZ G. HARRIS. 

